Abstract
Purpose: :
To describe the 4-year cause-specific incidence of visual impairment (VI) in a population-based sample of Latinos.
Methods: :
4, 520 Latinos 40 years and older from 6 census tracts in Los Angeles, California were recruited. All participants underwent a complete ophthalmologic examination, including measurement of best corrected visual acuity (BCVA) using Early Treatment for Diabetic Retinopathy Study protocol (ETDRS), refraction, complete anterior and posterior segment evaluation, intraocular pressure assessment, Humphrey Visual Field testing using a automated field analyzer, and optic disc and fundus photography. Diagnosis was based on all patient data that included ophthalmologic findings, lens grading using the lens opacity classification system II, fundus photographs, and visual fields. Visual acuity was converted to a logarithm of the minimal angle of resolution (Log MAR) score. Incidence of visual impairment was defined as BCVA worse than 20/40 and better than 20/200 at follow up in participants without previous visual impairment (BCVA 20/40 or better at baseline). The primary cause was assigned by the examining ophthalmologist to the condition that would be expected to produce the greatest limitation of vision. Frequencies of primary cause were calculated and differences were assessed using chi-square and trend tests across age and gender subcategories.
Results: :
There were 141 incident cases of VI, and of these the primary cause of visual impairment was identified in 112 participants. Of the 24 possible causes identified, the 4 most primary causes of VI were cataract (44.0%), diabetic retinopathy (15.6%), AMD (9.2%), and glaucoma (3.7%). Since cataract was the most common cause, age-specific and gender-specific rates were assessed. A significant trend with increasing age was found (p<0.001), but not for gender.
Conclusions: :
The leading causes of VI in this population of Latinos are mostly treatable or preventable. More effort and attention should be directed to screening and intervention.
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • cataract • visual impairment: neuro-ophthalmological disease